The protein encoded by this gene is a homeobox-containing developmental regulator associated with liver development. The encoded protein binds to the alpha-fetoprotein (AFP) gene promoter and increases the expression of AFP. This gene is overexpressed in some lung cancers and is linked to poor patient survival, possibly due to its resistance to cisplatin. This gene is aberrantly methylated in pancreatic cancer, deleted in squamous cell lung carcinomas, and acts as a tumor suppressor in esophageal cancer. Mutations in this gene may also be a cause of neural tube defects.